Mouthwashes are liquid preparations specifically designed to cleanse and refresh the mouth. While many early mouthwashes comprised no more than pleasantly flavored colored solutions having limited actual efficacy over the implied coverup of oral mal odor suggested by the persistence in the mouth of residual flavor components, consumer demand has resulted in the evolution of a new generation of rinses containing specific ingredients employed therein to provide efficacious action against problems associated in the oral cavity such as, for example, mal odor, caries, gum disorders and infections.
There is a wide latitude in the choice of conventional mouthwash ingredients and components depending upon the ultimate end purpose sought from the preparation. This end purpose serves as a basis of classifying various mouthwashes into specific categories.
There appears to be six basic categories of mouthwashes: cosmetic, astringent, buffered, deodorizing, therapeutic and antibacterial.
Cosmetic mouthwashes usually contain water, alcohol, flavor and color. They may also contain nonionic surface-active agents for the purpose of assisting in the solubilization of certain flavor components as well as aiding in the irrigation and cleansing of the mouth and teeth. Cosmetic mouthwashes have had excellent consumer acceptance as these "flavored water" formulations can be made quite attractive and very pleasant to taste.
Astringent mouthwashes provide a direct effect on the oral mucosa and also provide a means for flocculating and precipitating proteinaceous material so that it may be more readily removed by flushing. These mouthwashes by their very nature of being astringent present problems in flavoring and consumer acceptance.
Buffered mouthwashes may be helpful in reducing stringy saliva or reducing mucinous deposits by dispersion of protein based on the pH of the rinse. Critical pH values, however, can result in incompatability of ingredients and severe flavor problems.
Deodorizing mouthwashes heavily depend upon perfume to mask mal odor; however, some depend upon antibacterial or other mechanisms, unrelated to such action, for their effect. Those products employing antibacterial agents suffer from the aforementioned flavoring problems.
Therapeutic mouthwashes are formulated for the purpose of relieving infection, preventing dental caries, or mitigating some other pathological condition that may be associated with the mouth, teeth or throat. The nature of the therapeutic actives, their incompatibility with other ingredients in the rinse or for that matter synergistic effects resulting in questionable combinations present severe formulation problems in the more complex systems.
Finally, antibacterial mouthwashes, i.e. mouthwashes which are efficacious against bacteria found in the mouth, which is the primary subject matter of the instant invention, have the primary purpose of reducing or removing bacteria that are usually present in large numbers in the oral cavity. Microbial populations in the mouth arise quite naturally, for example, from dental plaque, decaying food particles and from salivary stagnation. In many instances these microbes are responsible either directly or indirectly for mal odor. Additionally, these microbes can present a source of infection and are believed by some investigators to be related at least in part to such problems as caries and periodontal disease.
A full treatment of mouthwash history and technology is presented by Rosenthal in Balsam et al. Cosmetics Science and Technology, John Wiley and Sons, 2nd. edition, 1972, Chapter 14 inclusive, which is incorporated herein by reference.
It is well known that some of the mal odorous elements of mouth aroma are generated by bacteria. It has been suggested that the germicidal agents commonly used in mouthwashes (quaternary ammonium compounds, phenolic compounds and sometimes flavor components having germicidal action) exert their effect by destroying or inhibiting oral bacteria. However, some have proposed that the antibacterial agents can exert a deodorizing effect on the oral cavity by a mechanism which is not related to their antibacterial activity. Rosenthal supra. There is evidence in the literature that antibacterial mouthwashes are more effective than would be expected from simple action of the flavor components of those mouthwashes; antibacterial activity probably therefore must be of some importance under certain circumstances, and direct deodorization by the antibacterial agent could also be involved, e.g. quaternary ammonium compounds could interact with aroma-producing chemicals in the mouth and thereby suppress them. Additionally, flavor undoubtedly plays a role in mouthwash activity,. While some flavors do have antimicrobial properties, and while it has been reported that mouthwashes comprising nothing more than flavored water can, to a limited extent, combat mouth aromas, such action is too minimal for a truly efficaceous product. It is more likely, however, that the major role of the flavor probably is simply to attempt to mask undesirable mal odors emanating from the mouth.
Attempts to improve efficacy against oral mal odor and other oral problems recently has resulted in increased stress on the importance of bacterial effectiveness. The compounds, however, that seem to demonstrate efficacy, at least at levels where bactericidal activity can be demonstrated, contribute significantly to flavor, foam, clarity and irritancy problems. Lacking physiological acceptance, these products have proved unacceptable to many consumers for a number of reasons. Examples of antibacterial agents employed in mouthwashes include phenolic compounds such as beta naphthol, thymol, carvacrol, chlorothymol, amyl-, hexyl-, heptyl and octylphenols, hexylresorcinol, hexachlorophene, and phenol; quaternary ammonium compounds such as quaternary morpholinium alkyl sulfates, cetylpyridinium chloride, alkyldimethyl benzylammonium chloride, and alkyltrimethylammonium halides; and miscellaneous antibacterial components such as benzoic acid, formaldehyde, potassium chlorate, tyrothrycin, gramicidin, iodine and iodine liberating compounds, and oxygen-bearing compounds such as sodium perborate, and urea peroxide. These compounds, however, have either a disagreeable taste, or are significantly effective only at levels where they cannot be effectively masked by flavorants. Many have been removed from the market by FDA action. Some are incompatible with other mouthwash ingredients, while still others have high and undesirable toxicity or sensitization potential or are otherwise under suspicion of being unsafe for unsupervised human use.
Thus, presently available mouthwashes that are effective against bacterial suffer generally from the single major deficiency that they are at best physiologically unacceptable to many users and perhaps could present some potential hazard under certain conditions. At the very minimum a product must be acceptable to the user if it is to be used to full advantage.
It is therefore an object of the instant invention to provide for an antibacterial mouthwash that is physiologically acceptable to the user.
It is a further object of the invention to achieve physiological acceptance by not relying upon conventional germicide agents to provide antibacterial action.
These and other objects of the invention which will become readily apparent in the continuing discussion below are provided for in Applicants' present invention which in one of its broadest aspects provides for physiologically acceptable, germicide free, stable liquid mouthwash comprising
(a) about 5 to 15 percent, by weight of said mouthwash, of ethanol; PA1 (b) about 0.1 to about 2 percent, by weight of said mouthwash, of an essential oil flavor mixture selected from the group consisting of spearmint, peppermint and mixtures thereof; PA1 (i) said mixture consists essentially of dodecyl sulfate salt and a tetradecyl sulfate salt wherein the cationic moiety of said salts is selected from the group consisting of sodium, potassium, magnesium, ammonium, and substituted ammonium ions and mixtures thereof, and PA1 (ii) wherein said dodecyl sulfate is present in said mixture in a weight ratio to said tetradecyl sulfate of about 4:1 to about 1:1 PA1 (i) water. PA1 (i) said mixture consists essentially of a dodecyl sulfate salt and a tetradecyl sulfate salt wherein the cationic moiety of said salt is selected from the group consisting of sodium, potassium, magnesium, ammonium, and substituted ammonium ions and mixtures thereof; and PA1 (ii) wherein said dodecyl sulfate is present in said mixture in a weight ratio to said tetradecyl sulfate of about 4:1 to about 1:1, PA1 (i) said mixture consists essentially of a dodecyl sulfate salt and a tetradecyl sulfate salt wherein the cationic moiety of said salt is selected from the group consisting of sodium, potassium, magnesium, ammonium, and substituted ammonium ions and mixtures thereof; and PA1 (ii) wherein said dodecyl sulfate is present in said mixture in a weight ratio to said tetradecyl sulfate of about 4:1 to about 1:1; PA1 (i) said mixture consists essentially of a dodecyl sulfate salt and a tetradecyl sulfate salt wherein the cationic moiety of said salt is selected from the group consisting of sodium, potassium, magnesium, ammonium, and substituted ammonium ions and mixtures thereof; and PA1 (ii) wherein said dodecyl sulfate is present in said mixture in a weight ratio to said tetradecyl sulfate of about 4:1 to about 1:1; PA1 (i) said mixture cnsists essentially of a dodecyl sulfate salt and a tetradecyl sulfate salt wherein the cationic moiety of said salts is selected from the group consisting of sodium, potassium, magnesium, ammonium, substituted ammonium and morpholenium ions and mixtures thereof, and PA1 (ii) wherein said dodecyl sulfate is present in said mixture in a weight rato to said tetradecyl sulfate of about 75:1 to about 1:1;
(c) about 0.1 to about 0.6 percent, by weight of said mouthwash, of an alkyl sulfate anionic surfactant mixture wherein:
(d) 0 to about 3 percent, by weight of said mouthwash, of a nonionic emulsifier;
(e) 0 to about 25 percent, by weight of said mouthwash, of a humectant;
(f) 0 to about 2 percent, by weight of said mouthwash, of an alkali metal halide;
(g) 0 to about 2 percent, by weight of said mouthwash, of a buffering salt pair, wherein said salt pair is capable of buffering said mouthwash to a pH of about 3 and about 8;
(h) 0 to about 2 percent, by weight of said mouthwash, of sodium saccharine, or an amount sufficient to provide a sweetening effect equivalent thereto of a sweetening agent; and
The composition as set forth above provides for a highly acceptable pleasant tasting mouth rinse that at the same time affords a high degree of antibacterial action. Additionally, this unique and specific combination affords several unique benefits heretofore unexpected that will become apparent in the detailed description of the invention to follow.